Mucocutaneous subdermal plexus flap for complete excision of a malignant dermal and conjunctival melanoma in a dog.

PURPOSE: To perform a reconstructive blepharoplasty to obtain complete surgical excision of a darkly pigmented raised conjunctival-eyelid mass of the lower eyelid in a dog. ANIMAL STUDIED: A 7-year-old, female-spayed, Yorkshire Terrier was evaluated for a slowly progressive, dark brown-to-black raised mass of the lower left eyelid. Sampling of the mass via fine-needle aspirate or incisional biopsy was declined, and an excision of the mass with the goal to obtain complete margins and maintain normal eyelid function with cosmesis was elected. PROCEDURES: The lower palpebral conjunctival-eyelid pigmented mass was excised en bloc and the lower eyelid was reconstructed with a mucocutaneous subdermal plexus flap. RESULTS: Histopathology revealed a malignant dermal and conjunctivalmelanoma excised with complete margins (1-2 mm). Short-term complications included corneal ulceration and eschar formation, which resolved completely at the 1-month follow-up. Long-term complications included mild trichiasis with epiphora and porphyrin staining. Tumor recurrence was not observed during an 8-month follow-up period. CONCLUSIONS: The en bloc excision with mucocutaneous subdermal plexus flap was successful in obtaining complete surgical margins for a malignant conjunctival-eyelid melanoma. An excellent functional and cosmetic outcome was achieved without tumor recurrence during an 8-month follow-up period. A mucocutaneous subdermal plexus flap can be considered as a surgical option for malignant melanoma of the lower eyelid.

Reproductive tract neoplasia in adult female Asian elephants (Elephas maximus).

Recent reports have highlighted a lower-than-expected prevalence of neoplasia in elephants and suggested mechanisms for cancer resistance. But despite infrequent reports in the literature, uterine neoplasia is common in managed Asian elephants (Elephas maximus). This study is an archival review of reproductive tract neoplasia in 80 adult female Asian elephant mortalities in managed care facilities in the United States from 1988 to 2019. Neoplasms occurred in 64/80 (80%) of cases. Most were in the uterus (63/64; 98%) with only a single case of ovarian neoplasia. Myometrial leiomyomas were present in 57/63 (90%) cases with uterine neoplasia. Uterine adenocarcinoma was present in 8/63 (13%) cases. Remaining cases included endometrial adenoma (2), focal carcinoma in situ in endometrial polyps (1), anaplastic carcinoma (1), endometrial hemangioma (1), primitive neuroectodermal tumor (PNET; 1), and angiosarcoma (1). One case with uterine adenocarcinoma had a separate pelvic mass histologically characterized as an anaplastic sarcoma. Distant metastases were documented in 5/8 (63%) cases of uterine adenocarcinoma, and in the uterine anaplastic carcinoma, PNET, and angiosarcoma. Four uterine adenocarcinomas and one carcinoma in situ were examined immunohistochemically for pan-cytokeratin, vimentin, and estrogen receptor. In all, neoplastic cells were pan-cytokeratin positive and vimentin negative, and in 2 cases were immunoreactive for estrogen receptor. Results show that female reproductive tract neoplasia, particularly of the uterus, is common in Asian elephants and is not limited to leiomyomas. Importantly, uterine neoplasms have the potential to impact fecundity and may represent obstacles to conservation in managed care.

Canine spontaneous head and neck squamous cell carcinomas represent their human counterparts at the molecular level.

Spontaneous canine head and neck squamous cell carcinoma (HNSCC) represents an excellent model of human HNSCC but is greatly understudied. To better understand and utilize this valuable resource, we performed a pilot study that represents its first genome-wide characterization by investigating 12 canine HNSCC cases, of which 9 are oral, via high density array comparative genomic hybridization and RNA-seq. The analyses reveal that these canine cancers recapitulate many molecular features of human HNSCC. These include analogous genomic copy number abnormality landscapes and sequence mutation patterns, recurrent alteration of known HNSCC genes and pathways (e.g., cell cycle, PI3K/AKT signaling), and comparably extensive heterogeneity. Amplification or overexpression of protein kinase genes, matrix metalloproteinase genes, and epithelial-mesenchymal transition genes TWIST1 and SNAI1 are also prominent in these canine tumors. This pilot study, along with a rapidly growing body of literature on canine cancer, reemphasizes the potential value of spontaneous canine cancers in HNSCC basic and translational research.

Leiomyoma of the third eyelid in a dog.

A 14-year-old neutered male Dachshund presented for the evaluation of oculus dexter (OD) third eyelid elevation ongoing for approximately 2 months. Complete ophthalmic examination revealed a large, nonpainful, well-demarcated, soft mass at the base of the right third eyelid causing elevation and mild hyperemia. The mass was freely moveable with the third eyelid, and no right globe deviation was noted. No other abnormalities were noted on physical examination, routine blood chemistry, complete blood count, serum T4, urinalysis, or urine cortisol/creatinine ratio. Ocular B-mode ultrasonography showed an anechoic, well-demarcated, homogenous, soft tissue mass at the base of the third eyelid with no orbital extension. A leiomyoma was diagnosed after multiple punch biopsies were obtained from the palpebral surface of the mass. The right third eyelid was excised surgically. Histopathology confirmed a completely excised, nodular, unencapsulated, expansile mass within the third eyelid. Positive smooth muscle actin and negative S-100 immunohistochemistry confirmed a leiomyoma. Bundles of normal smooth muscle were also present adjacent to the mass. The mass was compressing the adjacent lacrimal gland and associated with moderate dacryoadenitis. Twelve months postoperatively, the right globe position and motility remain normal with no evidence of mass regrowth. To the author's knowledge, this is the first reported case of a leiomyoma of the third eyelid in any species. In this case, the mass was completely excised and no regrowth has occurred twelve months after surgery. This case along with independently reviewed canine third eyelids clearly demonstrates the presence of smooth muscle within the canine third eyelid.

Protozoal infections of the cornea and conjunctiva in dogs associated with chronic ocular surface disease and topical immunosuppression.

OBJECTIVE: To describe five cases of protozoal keratitis or conjunctivitis in dogs with chronic preexisting ocular surface disease treated with long-term immunosuppression. ANIMALS STUDIED: Five dogs that developed corneal or conjunctival mass lesions. PROCEDURES: The database of the Comparative Ocular Pathology Laboratory of Wisconsin was searched for canine cases diagnosed with corneal or conjunctival protozoal infection. Five cases were identified, and tissues were examined using routine and special histochemical stains: immunohistochemical labels for Neospora caninum, Toxoplasma gondii, and Leishmania spp., and tissue sample PCR for Leishmania spp., Trypanosoma cruzi, tissue coccidia (i.e., T. gondii/Sarcocystis/Neospora), piroplasms, trichomonads, and Acanthamoeba. Electron microscopy was performed for two cases, and serology for N. caninum and T. gondii was available for three cases. RESULTS: Preexisting ocular diseases included keratoconjunctivitis sicca and pigmentary keratitis (n = 4) and pyogranulomatous meibomian adenitis (n = 1). All dogs were treated with tacrolimus or cyclosporine for at least 1.2 years. Dogs were presented with fleshy corneal or conjunctival masses that were clinically suspected to be neoplastic (n = 4) or immune mediated (n = 1). Histologic examination revealed granulomatous inflammation with intralesional protozoal organisms. Amoeba (n = 2), T. gondii (n = 2), or Leishmania mexicana (n = 1) were identified using molecular techniques. Serological tests were negative. CONCLUSIONS: Protozoal keratitis and conjunctivitis without systemic involvement appears rare and may be associated with chronic preexisting ocular surface disease treated with long-term immunosuppression. Based upon clinical appearance, lesions could be confused with neoplasia. This is the first report of amoebic keratoconjunctivitis in dogs and of L. mexicana in dogs in the United States.

Penetrating sclerokeratoplasty and autologous pinnal cartilage and conjunctival grafting to treat a large limbal melanoma in a dog.

A four-year-old neutered male Labrador retriever presented to Portland Veterinary Specialists Ophthalmology Service for evaluation of a pigmented mass oculus sinister (OS) of approximately 4-month duration. Complete ophthalmic examination revealed a large, pigmented, raised, well-demarcated, epibulbar mass appearing to originate from the nasodorsal limbal region. The mass was smooth and roughly circular, extending approximately 4 mm into the sclera and 14 mm into the nasodorsal cornea. Gonioscopy directly under the mass was not possible due to mass size. The visible iridocorneal angle was normal. High-resolution B-scan ultrasound showed mass extension to Descemet's membrane and deep sclera, but no intraocular invasion. Penetrating sclerokeratoplasty was performed followed by autologous pinnal cartilage and conjunctival grafting to repair the corneoscleral defect (20 mm x 19 mm) and to restore globe integrity and function. Histopathology confirmed the mass to be a benign limbal melanoma with complete excision. The surgery site healed without complication, and the pinnal cartilage became fully incorporated into the globe. Twelve months postoperatively, the patient remains visual with a normal intraocular and fundic examination. The pinnal harvest site on the right ear healed without complication. To the authors' knowledge, this is the first reported case of corneoscleral grafting using autologous pinnal cartilage. This may represent a viable alternative to other corneoscleral grafting procedures for large defects and is an attractive treatment option due to lack of host rejection, readily available source of donor cartilage, and provision of tectonic support to the globe.

Use of a Nitinol Wire Stent for Management of Severe Tracheal Stenosis in an Eclectus Parrot (Eclectus roratus).

A 25-year-old, female eclectus parrot (Eclectus roratus) presented for dyspnea 3 weeks after anesthesia and surgery for egg yolk coelomitis. Radiography, computed tomography, and tracheoscopy revealed multiple tracheal strictures spanning a length of 2.6 cm in the mid to distal trachea. Histopathologic examination revealed mild fibrosis, inflammation, and hyperplasia consistent with acquired tracheal strictures. Tracheal resection was not considered possible because of the length of the affected trachea. The strictures were resected endoscopically, and repeated balloon dilation under fluoroscopic guidance over the course of 10 months resulted in immediate but unsustained improvement. Computed tomography was used to measure the stenotic area. A 4 × 36-mm, custom-made, nitinol wire stent was inserted into the trachea under fluoroscopic guidance. After stent placement, intermittent episodes of mild to moderate dyspnea continued, and these responded to nebulization with a combination of saline, acetylcysteine, and dexamethasone. Multiple attempts to wean the patient off nebulization therapy and to switch to a corticosteroid-free combination were unsuccessful. The parrot eventually developed complications, was euthanatized, and necropsy was performed. Histologically, the tracheal mucosa had widespread erosion to ulceration, with accumulation of intraluminal exudate and bacteria, severe degeneration of skeletal muscle and tracheal rings, prominent fibrosis, and mild to moderate, submucosal inflammation. Clinicopathologic findings in this case suggested tracheomalacia, which has not been previously described in birds. Custom-made tracheal stents can be used for severe tracheal stenosis in birds when tracheal resection and anastomosis is not possible. Complications of tracheal stent placement in birds may include tracheitis and tracheomalacia. To our knowledge, this is the first report of tracheal stent placement in an avian species.

Parasites and vector-borne pathogens of southern plains woodrats (Neotoma micropus) from southern Texas.

From 2008 to 2010, southern plains woodrats (Neotoma micropus) from southern Texas, were examined for parasites and selected pathogens. Eight helminth species were recovered from 97 woodrats including, Trichuris neotomae from 78 (prevalence = 80%), Ascarops sp. from 42 (43%), Nematodirus neotoma from 31 (32%), Raillietina sp. from nine (9%), Taenia taeniaeformis larvae from eight (8%), and an unidentified spiurid, a Scaphiostomum sp. and a Zonorchis sp. each from a single woodrat. Besnotia neotomofelis was detected in three (3%) woodrats and microfilaria were detected in seven (7%). Polymerase chain reaction (PCR) testing of blood samples from 104 woodrats detected a novel Babesia sp. in one (1%) and Hepatozoon sp. in 17 (16%) woodrats. Partial 18S rRNA gene sequence of the Babesia was 94% similar to B. conradae. Histologic examination of tissues detected intestinal coccidia in seven of 104 (7%), Sarcocystis neotomafelis in 26 (25%), Hepatozoon sp. in 21 (20%), and Dunnifilaria meningica in four (4%) woodrats. Three woodrats (5%) were seropositive for Toxoplasma gondii. Ectoparasites recovered included fleas (Orchopeas sexdentatus and O. neotomae), ticks (Ixodes woodi and Ornithodoros turicata), mites (Trombicula sp. and Ornithonyssus (Bdellonyssus) bacoti) and bot flies (Cuterebra sp.). The only difference in prevalence related to gender was for N. neotoma (males > females, p = 0.029). Prevalence of T. neotomae and all intestinal parasites combined was significantly higher in adults compared with juveniles (p = 0.0068 and p =0.0004), respectively. Lesions or clinical signs were associated with Cuterebra and B. neotomofelis. Collectively, these data indicate that woodrats from southern Texas harbor several parasites of veterinary and/or medical importance.

Debilitation and mortality associated with besnoitiosis in four Virginia opossums (Didelphis virginiana).

Besnoitia spp. are coccidian parasites that infect a variety of wild and domestic mammals as well as some reptiles. Although infection with Besnoitia is common in Virginia opossums (Didelphis virginiana), clinical signs or death due to Besnoitia is rare. This manuscript describes four Virginia opossums that had severe clinical disease and inflammation associated with besnoitiosis. Clinical signs included trembling, incoordination, circling, blindness, poor body condition, and sudden death. Gross lesions included parasitic cysts in eyes, skin, and visceral organs. Histologically, cysts were often degenerate and associated with mild to marked inflammation, and amyloidosis was noted in one animal. Polymerase chain reaction and sequencing confirmed Besnoitia darlingi in three of the four opossums.

Cuterebrid myiasis (Diptera: Oestridae) in captive ring-tailed lemurs (Lemur catta) at a South Carolina zoo.

In September 2008, two ring-tailed lemurs (Lemur catta), comprising a mother-daughter pair, at the Greenville Zoo, Greenville, South Carolina, USA, were diagnosed with cuterebrid myiasis (Diptera: Oestridae) subsequent to sudden death of the adult lemur. On necropsy, a single bot warble was discovered in the subcutis of the axillary region. Histopathology revealed a severe eosinophilic bronchopneumonia. The juvenile lemur was inspected and found to have warbles on three separate dates in late September. One representative bot fly larva was identified as a Cuterebra sp. that normally infests lagomorphs in the southeastern United States. Cuterebrid myiasis is rarely reported in lemurs and has not been previously associated with pneumonia or death in these animals.

Experimental infection of two South American reservoirs with four distinct strains of Trypanosoma cruzi.

Trypanosoma cruzi (Tc), the causative agent of Chagas disease, is a diverse species with 2 primary genotypes, TcI and TcII, with TcII further subdivided into 5 subtypes (IIa-e). This study evaluated infection dynamics of 4 genetically and geographically diverse T. cruzi strains in 2 South American reservoirs, degus (Octodon degus) and grey short-tailed opossums (Monodelphis domestica). Based on prior suggestions of a genotype-host association, we hypothesized that degus (placental) would more readily become infected with TcII strains while short-tailed opossums (marsupial) would be a more competent reservoir for a TcI strain. Individuals (n=3) of each species were intraperitoneally inoculated with T. cruzi trypomastigotes of TcIIa [North America (NA)-raccoon (Procyon lotor) origin], TcI [NA-Virginia opossum (Didelphis virginiana)], TcIIb [South America (SA)-human], TcIIe (SA-Triatoma infestans), or both TcI and TcIIa. Parasitaemias in experimentally infected degus peaked earlier (7-14 days post-inoculation (p.i.)) compared with short-tailed opossums (21-84 days p.i.). Additionally, peak parasitaemias were higher in degus; however, the duration of detectable parasitaemias for all strains, except TcIIa, was greater in short-tailed opossums. Infections established in both host species with all genotypes, except for TcIIa, which did not establish a detectable infection in short-tailed opossums. These results indicate that both South American reservoirs support infections with these isolates from North and South America; however, infection dynamics differed with host and parasite strain.

Aelurostrongylus abstrusus larvae in the colon of two cats.

A 12-year-old male domestic shorthair cat with a history of depression, aggression, and fever was presented for necropsy, and formalin-fixed tissues from a second male domestic shorthair cat of unknown age were submitted for histopathologic examination to the Athens Veterinary Diagnostic Laboratory. Both cats had granulomatous pneumonia associated with large numbers of parasite eggs and larvae, consistent with Aelurostrongylus abstrusus. Both cats also had larvae within glands in the colon that were identified morphologically as A. abstrusus first-stage larvae.

Gingival osteogenic melanoma in two dogs.

Osteogenic melanoma is a rare variant of metaplastic malignant melanoma in human medicine and appears to be a similarly rare variant in dogs. Two dogs with oral malignant melanoma with neoplastic bone formation are reported in this study. Both tumors were characterized by malignant melanocytes that transitioned into neoplastic bone at the deep margins of the neoplasm. Immunohistochemical analysis revealed S100- and Melan-A-positive neoplastic cells adjacent to, and occasionally embedded within, an osteoid and chondroblastic matrix. Scattered clusters of neoplastic cells were also positive for osteocalcin. The findings indicate that in dogs, as in humans, neoplastic melanocytes have metaplastic potential and can be osteogenic.

Oral transmission of Trypanosoma cruzi with opposing evidence for the theory of carnivory.

We present the first demonstration of oral transmission of Trypanosoma cruzi to raccoons (Procyon lotor), a natural reservoir host in the United States, by ingestion of trypomastigotes and infected bugs, but not infected tissue. To investigate an alternative, non-vector-based transmission method, we tested the hypothesis that raccoons scavenging on infected hosts results in patent infection. Macerated tissue from selected organs infected with amastigote stages of T. cruzi was orally administered to experimental groups of raccoons (n = 2/group) at 2, 12, or 24 hr after collection of the tissue samples. Additionally, raccoons (n=1) in control groups were inoculated intravenously or per os with trypomastigotes. To further elucidate transmission routes of T. cruzi to raccoons, infected Rhodnius prolixus were fed to raccoons (n=2). Raccoons did not become infected after ingestion of amastigote-infected tissues as evidenced by negative polymerase chain reaction results from blood and tissue, lack of seroconversion, and negative parasitemias. However, per os transmission can occur by ingestion of the infective trypomastigote stage or infected reduviid bugs. We conclude from these findings that oral transmission of T. cruzi may be a route of infection for wildlife in sylvatic cycles, but the scavenging behavior of animals is not likely a significant transmission route.

Characterization of Sarcocystis from four species of hawks from Georgia, USA.

During 2001 to 2004, 4 species of hawks (Buteo and Accipiter spp.) from Georgia were surveyed for Sarcocystis spp. infections by examining intestinal sections. In total, 159 of 238 (66.8%) hawks examined were infected with Sarcocystis spp. Samples from 10 birds were characterized by sequence analysis of a portion of the 18S rRNA gene (783 base pairs). Only 3 of the 10 sequences from the hawks were identical; the remainder differed by at least 1 nucleotide. Phylogenetic analysis failed to resolve the position of the hawk Sarcocystis species, but they were closely related several Sarcocystis species from raptors, rodents, and Sarcocystis neurona. The high genetic diversity of Sarcocystis suggests that more than 1 species infects these 4 hawk species; however, additional molecular or experimental work will be required to determine the speciation and diversity of parasites infecting these avian hosts. In addition to assisting with determining species richness of Sarcocystis in raptors, molecular analysis should be useful in the identification of potential intermediate hosts.

Outbreaks of renal failure associated with melamine and cyanuric acid in dogs and cats in 2004 and 2007.

Sixteen animals affected in 2 outbreaks of pet food-associated renal failure (2 dogs in 2004; 10 cats and 4 dogs in 2007) were evaluated for histopathologic, toxicologic, and clinicopathologic changes. All 16 animals had clinical and laboratory evidence of uremia, including anorexia, vomiting, lethargy, polyuria, azotemia, and hyperphosphatemia. Where measured, serum hepatic enzyme concentrations were normal in animals from both outbreaks. All animals died or were euthanized because of severe uremia. Distal tubular lesions were present in all 16 animals, and unique polarizable crystals with striations were present in distal tubules or collecting ducts in all animals. The proximal tubules were largely unaffected. Crystals and histologic appearance were identical in both outbreaks. A chronic pattern of histologic change, characterized by interstitial fibrosis and inflammation, was observed in some affected animals. Melamine and cyanuric acid were present in renal tissue from both outbreaks. These results indicate that the pet food-associated renal failure outbreaks in 2004 and 2007 share identical clinical, histologic, and toxicologic findings, providing compelling evidence that they share the same causation.

West Nile virus antibody prevalence in American crows (Corvus brachyrhynchos) and fish crows (Corvus ossifragus) in Georgia, USA.

Crows have been the centerpiece of avian West Nile virus (WNV) surveillance and research in North America. This work has demonstrated variation in susceptibility to WNV infection between American (Cor vus brachyrhynchos) andFish Crows (Corvus ossifragus). The higher WNV-associated mortality rate in American Crows compared with Fish Crows suggests that WNV antibody prevalence would be greater in the Fish Crow population. The objectives of this study were to 1) determine whether Fish Crows had higher WNV antibody prevalencethan American Crows, 2 ) determine th e persistence o f antibodies to WNV in naturally infected Fish Crows, and 3) develop a technique to distinguish Fish Crows from American Crows on the basis of sequence analysis and restriction enzyme digestion of a mitochondrial DNA fragment. West Nile virus antibody prevalence was 16.5% (n = 97) in Fish Crows and 5.7% in American Crows (n = 53) collected from Georgia between 2004 and 2006. Antibodies persisted at high titers for 12 mo in Fish Crows. This is the first report of WNV antibody persistence in a crow species. A polymerase chain reaction technique paired with restriction enzyme digestion easily distinguished American Crows from Fish Crows on the basis of a mitochondrial DNA fragment.

Pathology and epidemiology of natural West Nile viral infection of raptors in Georgia.

Carcasses from 346 raptors found between August 2001 and December 2004 were tested for West Nile virus (WNV) using virus isolation and immunohistochemistry; 40 were positive for WNV by one or both methods. Of these 40 birds, 35 had histologic lesions compatible with WNV infection, one had lesions possibly attributable to WNV, and four had no histologic evidence of WNV. The most common histologic lesions associated with WNV infection were myocardial inflammation, necrosis, and fibrosis; skeletal muscle degeneration, inflammation, and fibrosis; and lymphoplasmacytic encephalitis. Other lesions included hepatitis, lymphoid depletion in spleen and bursa, splenic and hepatic hemosiderosis, pancreatitis, and ganglioneuritis. Gross lesions included calvarial and leptomeningeal hemorrhage, myocardial pallor, and splenomegaly. Red-tailed hawks (Buteo jamaicensis) (10/56), sharp-shinned hawks (Accipiter striatus) (8/40), and Cooper's hawks (Accipiter cooperii) (10/103) were most commonly affected. Also affected were red-shouldered hawks (Buteo lineatus) (2/43), an osprey (Pandion haliaetus) (1/5), barred owls (Strix varia) (4/27), a great horned owl (Bubo virginianus) (1/18), and eastern screech owls (Megascops asio) (4/42). Although birds were examined throughout the year, positive cases occurred only during the summer and late fall (June-December). Yearly WNV mortality rates ranged from 7-15% over the four years of the study. This study indicates trends in infection rates of WNV in raptorial species over a significant time period and supports the available information regarding pathology of WNV infection in Strigiformes and Falconiformes. Although many species tested were positive for WNV infection, severity of lesions varied among species.

Evaluation of gastroscopy and biopsy of the proventriculus and ventriculus in pigeons (Columba livia).

OBJECTIVE To evaluate the efficacy and safety of gastroscopy and biopsy of the proventriculus and ventriculus in pigeons (Columba livia). ANIMALS 15 adult pigeons. PROCEDURES Each pigeon was anesthetized, and the upper gastrointestinal tract (from the cervical portion of the esophagus to the ventriculus) was endoscopically evaluated by use of a rigid endoscope inserted orally. Saline (0.9% NaCl) solution was orally infused to achieve lumen dilation and visibility. Two mucosal biopsy specimens were collected from each of the proventriculus and ventriculus, histologically evaluated, and graded for crush artifacts and depth. Pigeons were monitored for adverse effects for 3 to 6 days after the procedure, after which they were euthanized for necropsy. RESULTS Gastroscopy via the oral approach provided excellent visibility of the lumen and mucosal surfaces of the proventriculus and cranial portion of the ventriculus and was safe provided that appropriate precautions were taken. Two intraoperative deaths occurred at the beginning of the study; following procedure refinement, no additional deaths occurred. No major adverse effects of the procedure were detected in the remaining 13 pigeons during the postoperative monitoring period or at necropsy. Diagnostic quality of proventriculus specimens was adequate for 10 of 13 pigeons. Eight of 13 ventriculus specimens were of inadequate quality, and only 3 were of adequate quality. CONCLUSIONS AND CLINICAL RELEVANCE Gastroscopy was useful for evaluating the lumen and mucosal surface of the proventriculus and ventriculus in pigeons, and biopsy of those organs was safely performed with the appropriate technique. Further evaluation of these techniques is needed in birds with clinical disease and birds of other species.

West Nile virus detection in the organs of naturally infected blue jays (Cyanocitta cristata).

Blue jays (Cyanocitta cristata) are an effective indicator species for West Nile virus (WNV) and may be regionally important in surveillance efforts. The sites of WNV replication and sensitivity of virus detection techniques are undefined for blue jays. The objectives of this study were to describe the gross and microscopic pathology associated with natural WNV infection in blue jays, as well as determine the most appropriate tissues to be used for virus isolation, reverse transcription-nested polymerase chain reaction, and immunohistochemistry (IHC) techniques. Blue jays were collected in Georgia, USA, between May and September 2001. Initial screening by virus isolation indicated that 36 of 59 blue jays chosen for evaluation were WNV positive. From this group, 20 positive and five negative birds were chosen to compare virus detection techniques. Six positive and five negative birds were selected for histopathology examination. Splenomegaly and poor body condition were the most consistent gross findings among positive birds. The most consistent histopathologic findings in the tissues of WNV-positive blue jays were mononuclear leukocytosis and epicarditis/myocarditis. Brain, heart, and lung had the highest viral titers, and WNV antigen was most often detected by IHC in heart, kidney, liver, and lung. Reverse transcription-nested polymerase chain reaction proved to be the most sensitive diagnostic test applied in this study irrespective of the tissue type. Brain tissue could be used effectively for both virus isolation and RT-nPCR, and this tissue is simple to remove and process. The success of IHC is highly dependent on tissue selection, and the use of multiple tissues including heart, kidney, liver, or lung is recommended.